著者

Atsu Yamasaki Junko Kaneyoshi Michiharu Nakano Akira Kitajima

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-284, (Released:2022-06-01)

被引用文献数

1

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Mukaku Kishu–type seedlessness in citrus (Citrus L.) is characterized by the formation of small and edible seeds (type A seeds) with an immature seed coat and arrest of embryo development at an early stage. We investigated the effect of high temperature on embryo and seed development in the Mukaku Kishu–type seedless cultivar ‘Southern Yellow’ over a period of four years. In outdoor-grown trees, embryos at the zygote and proembryo stages were observed at 10 weeks after pollination (WAP), and embryo development was largely arrested at 18 WAP; as a result, only type A seeds formed. In glasshouse-grown trees, globular-stage embryos were observed at 10 WAP, and globular- to cotyledon-stage embryos developed by 18 WAP. The day temperature in the glasshouse was higher than outdoors. Seeds developed in the fruit of trees transferred into a glasshouse at 0–2, 0–4, or 2–4 WAP, but not 4–8 WAP. High temperature before flowering had no effect on seed development. We conclude that high temperature at 0–4 WAP releases the arrest of embryo development after 10 WAP in ‘Southern Yellow’.

著者

Hiroshi Yakushiji Atsu Yamasaki Shozo Kobayashi Junko Kaneyoshi Akifumi Azuma Hiroyoshi Sugiura Akihiko Sato

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.MI-080, (Released:2015-12-29)

被引用文献数

4

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‘Hasshu’, a dwarf budsport that originated from the leading persimmon cultivar ‘Hiratanenashi’ (Diospyros kaki Thunb.), was discovered in Japan in 2005. Although ‘Hiratanenashi’ is seedless because of anisoploidy (2n = 135 = 9x), ‘Hasshu’ produces some small normal seeds. In this study, we investigated differences in the morphological characteristics of the vegetative organs and fruits and in the ploidy level between ‘Hasshu’ and ‘Hiratanenashi’. The shoot length, internode length, and leaf size of ‘Hasshu’ were smaller than those of ‘Hiratanenashi’. ‘Hasshu’ bore smaller flowers than those of ‘Hiratanenashi’ in late May, and had consistently smaller fruit than ‘Hiratanenashi’ at all fruit development stages. ‘Hasshu’ ripened in late October, similar to ‘Hiratanenashi’. Both ‘Hiratanenashi’ and ‘Hasshu’ are pollination-variant astringent (PVA) cultivars. Except for the deletion of one allele at ssrdk10, no differences were detected between the two cultivars at four simple sequence repeat (SSR) marker loci. By flow cytometric analysis and chromosome observation, we confirmed that ‘Hasshu’ was octoploid (2n = 120 = 8x), indicating that it was both a dwarf and a ploidy-reduction mutation. These results suggest that recovery of the ability to produce some normal seeds by ‘Hasshu’ may have been caused by the change in ploidy from anisoploid to isoploid.